Methane | Definition, Properties, Uses, & Facts | Britannica

Trang chủ » Ch4 » Methane | Definition, Properties, Uses, & Facts | Britannica

Có thể bạn quan tâm

Role as a greenhouse gas

Methane that is produced and released into the atmosphere is taken up by methane sinks, which include soil and the process of methane oxidation in the troposphere (the lowest atmospheric region). Most methane produced naturally is offset by its uptake into natural sinks. Anthropogenic methane production, however, can cause methane concentrations to increase more quickly than they are offset by sinks. Since 2007 methane concentrations in Earth’s atmosphere have increased by 6.8–10 parts per billion (ppb) per year. By 2022 atmospheric methane had reached 1908.61 ppb, about three times higher than preindustrial levels, which hovered at 600–700 ppb.

Key People: Alessandro Volta (Show more) Related Topics: natural gas greenhouse gas decarbonization Do Cows Pollute as Much as Cars? triphenylmethane (Show more) On the Web: IOPscience - The Astrophysical Journal - Methane Formation Efficiency on Icy Grains: Role of Adsorption States (PDF) (Dec. 06, 2025) (Show more) See all related content

Increased concentrations of methane in the atmosphere contribute to the greenhouse effect, whereby greenhouse gases (particularly carbon dioxide, methane, and water vapour) absorb infrared radiation (net heat energy) and reradiate it back to Earth’s surface, potentially trapping heat and producing substantial changes in climate. Increased atmospheric methane also adds to the greenhouse effect indirectly. For example, in methane oxidation, hydroxyl radicals (OH−) remove methane by reacting with it to form carbon dioxide and water vapour, and as concentrations of atmospheric methane increase, concentrations of hydroxyl radicals decrease, effectively prolonging the atmospheric lifetime of methane.

Access for the whole family! Bundle Britannica Premium and Kids for the ultimate resource destination. Subscribe The Editors of Encyclopaedia Britannica

Từ khóa » Ch4